Year	Number
2007-01-01	1
2008-01-01	1
2009-01-01	3
2010-01-01	6
2011-01-01	8
2012-01-01	7
2013-01-01	10
2014-01-01	10
2015-01-01	11
2016-01-01	10
2017-01-01	9